Extra: The Smartest Kid Championship

Extra: The Smartest Kid Championship is a Extra chapter of Sora no Otoshimono manga.

Basically a chapter about Astraea and Tomoki having random contests to find out who, between the two of them, is actually the dumbest in Sorami. This came after the challenge that he along with Sohara, Mikako, Astraea, and Nymph participated in at their school.